Interfixated vertebral body replacement and insertion methods

ABSTRACT

Implants and instruments for providing an ideal trajectory for the insertion of instruments and screws during implantation of an interbody implant in a spinal surgery are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional of and claims priority to U.S.Provisional Application No. 62/273,377, filed on Dec. 30, 2015, U.S.Provisional Application No. 62/273,445, filed Dec. 31, 2015, and U.S.Provisional Application No. 62/273,443, filed on Dec. 31, 2015, theentire disclosures of which are incorporated herein by reference.

BACKGROUND

Field of the Disclosure

The present disclosure relates generally to medical devices, morespecifically spinal implants, implant insertion assemblies, implantinsertion guides, and surgical methods for replacing at least a portionof one or more vertebral bodies of the spine.

Background

The spine is formed of a column of vertebra that extends between thecranium and pelvis. The three major sections of the spine are known asthe cervical, thoracic and lumbar regions. There are 7 cervicalvertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae, with each ofthe 24 vertebrae being separated from each other by an intervertebraldisc. A series of about 9 fused vertebrae extend from the lumbar regionof the spine and make up the pelvic region of the vertebral column.These fused vertebrae consist of the sacral and coccygeal region of thevertebral column.

The main functions of the spine are to provide support and protect thespinal cord. Even slight disruptions to either the intervertebral discsor vertebrae can result in serious discomfort due to compression ofnerve fibers either within the spinal cord or extending from the spinalcord. If a disruption to the spine becomes severe enough, damage to anerve or part of the spinal cord may occur and can result in partial tototal loss of bodily functions (e.g. walking, talking, and breathing).

Each year millions of people suffer from back pain arising from defectsin the intervertebral disc space. Commonly, surgical interventionsdirected at promoting fusion across the affected joint are employed topermanently provide long term pain relief to the patient. Typically,such fusion surgeries involve performing a partial or completediscectomy to prepare the disc space, and then implanting a natural orsynthetic intervertebral fusion implant within the prepared disc space.

SUMMARY

The present application describes implants and instruments forperforming surgical procedures on the spine, including one or more forproviding an ideal trajectory for the insertion of instruments andscrews during implantation of an interbody implant.

According to one example, an insertion guide providing an idealtrajectory for placement of instruments during implantation of aninterbody implant in a spinal surgery is described. The insertion guidehas a central body, an inserter tab stop, and one or more cylindricalguide tubes. There is an aperture through the central body forinteraction with an insertion tool. The inserter stop extends from thetrailing end of the insertion guide to interact with an insertion tool.The guide tubes are generally cylindrical with a lumen and are set atfixed angles that correspond with the angles of the screw holes in aninterbody implant.

According to another aspect, the insertion guide may have an engagementmechanism on the inserter stop tab that allows a secure and reversibleinterconnection of the guide with an insertion tool.

According to another aspect, the insertion guide may have ageometrically shaped edge at the trailing end of the guide tubes toprovide secure engagement with an insertion tool. According to anotheraspect, the geometric edge may have crenellations.

According to another aspect, the insertion guide may be made of aradiolucent material. According to another aspect, the insertion guidemay be made of aluminum which is both radiolucent and light weight.

According to another aspect, the insertion guide may have between oneand four guide tubes according to the surgical need. In some aspects,the insertion guide has one guide tube. In another aspect, the insertionguide has three tubes.

According to a second example, an insertion instrument that provides anideal trajectory for placement of instruments during implantation of aninterbody implant is described. The insertion instrument comprises anelongate tubular element, thumbwheel, and an insertion head. Theinsertion head has one fixed arm and one pivoting arm. The tubularelement has an internal draw rod with a threaded portion that interactswith a threaded portion of the lumen of the thumbwheel. Rotation of thethumbwheel results in movement of the internal draw rod which in turnmoves the pivoting arm. Connected to the upper surface of the insertionhead is an insertion guide tube positioned at an appropriate angle toalign with a screw hole on the interbody implant.

According to another aspect, the insertion instrument has an adjustableinsertion guide tube attached to the insertion head at a pivoting joint.The pivoting guide tube has a fixed guide post attachment to allowrepositioning. The guide post is sized to slide within an aperturethrough the insertion head. The position of the guide tube may be fixedby insertion of a set screw which contacts the guide post and preventsmovement.

According to a third example a driver for insertion of bone screwsduring spinal surgery is described. The driver comprises a central shaftwith two rotation grips located at the proximal end and a driver tip andhexabit driver located at the distal end. The driver tip engages thescrew, and the hexabit driver engages the set screw. The first rotationgrip rotates the driver tip to set the screw. The second rotation griprotates the hexabit driver to set the set screw. The driver alsoincludes an indicator that the screw is properly seated. When the screwis properly set, the driver provides one or more indicators that may bevisual, audible, or tactile.

According to another aspect, the driver may have a driver tip that movesrelative to the shaft of the driver. As the screw is set, the driver tipmoves. The indicator may be a colored band that is covered by the drivertip when the screw is properly seated.

According to another aspect, the driver may include a sleeve locatednear the driver tip. The sleeve rotates and moves relative to thedriver. Beneath the sleeve are a button, internal spline, and a spring.The spline is composed of a series of lengthwise grooves arranged aroundthe outer surface of the driver near the driver tip. The spring is woundaround the spline. When a screw is inserted, the sleeve moves andcompresses the spring. When the screw is properly set, the button popsto give an audible and visual indicator giving a tactile indicator thatthe screw is properly set. A spline pin may interact with the spline toprevent additional rotation, giving a tactile indicator that the screwis properly set.

According to a fourth example, a system for insertion of a bone screw atan ideal trajectory during spinal surgery is described. The systemcomprises an interbody implant, an insertion guide, an insertioninstrument, and a driver. The interbody implant has one or more screwholes and one or more holes for an insertion instrument. The insertionguide has one or more guide tubes aligned with the screw holes of theinterbody implant, and has one or more holes for an insertioninstrument. The insertion instrument has one or more arms that are sizedto pass through the holes of the guide and the interbody implant toreversibly connect all three pieces together. The driver tip is sized topass through the guide tubes and the screw holes to the desired site forinsertion of the screws.

According to a fifth example, an insertion instrument for placement ofinstruments during implantation of an interbody implant is described.The insertion instrument comprises a hollow elongate tubular elementwith a thumbwheel and an insertion head at opposite ends. The thumbwheelis generally cylindrical with a threaded lumen. There is an inner shaftwithin the bore of the tubular element. The inner shaft has a threadedportion that engages with the threaded portion of the lumen of thethumbwheel so that rotation of the thumbwheel results in movement of theinner shaft. The insertion head has one or more insertion arms thatproject forward and that are sized to pass through correspondinginsertion holes on a guide and an interbody implant to reversiblyconnect the insertion instrument to the guide and the interbody implant.The lower surface of the insertion head includes a keyed mechanism tointerlock with a complementary feature on the insertion guide.

According to a sixth example, an interbody implant for insertion of abone screw at an ideal trajectory during spinal surgery s described. Theinterbody comprises a top surface, a bottom surface, two opposing sidewalls, a leading end, and a trailing end. The top and bottom surfacesinclude anti-migration features. One or more screw holes extend throughthe implant at an angle from the trailing end to the top or bottomsurface. The screw holes have an interior spherical surface thatinteracts with a fully seated screw. The implant includes one or moreinsertion holes through the trailing end. The implant also includes oneor more insertion recesses on the opposing side wall for interactionwith an insertion instrument.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-D show alternative views of an interfixated interbody implantaccording to one embodiment. FIG. 1A shows a perspective view. FIG. 1Bshows a sectional view. FIG. 1C shows a rear view. FIG. 1D shows a sideview.

FIG. 2 shows a rear perspective view of a 3-hole guide according to anexemplary embodiment.

FIG. 3 shows a rear view of the guide of FIG. 2.

FIG. 4 shows a front view of the guide of FIG. 2.

FIG. 5 shows an insertion assembly comprising an implant, 3-hole guide,and insertion instrument according to an exemplary embodiment.

FIG. 6 shows a side perspective view of the guide of FIG. 2 incombination with the implant of FIG. 1.

FIG. 7 shows a side view of the implant of FIG. 1 in combination with a1-hole guide.

FIG. 8 shows a side perspective of the 1-hole guide of FIG. 7.

FIG. 9 shows a rear view of the guide of FIG. 7.

FIG. 10 shows a front view of the guide of FIG. 7.

FIG. 11 shows an insertion assembly comprising an implant, 1-hole guide,and insertion instrument according to an exemplary embodiment.

FIG. 12 shows a perspective view of an inserter according to oneembodiment.

FIG. 13 shows a bottom view of the inserter of FIG. 12.

FIG. 14 shows a top view of the inserter of FIG. 13.

FIG. 15 shows a side view of the inserter of FIG. 13.

FIG. 16A-C show alternative views of an implant and a guide tubeinsertion instrument in the open position. FIG. 16A shows a top view.FIG. 16B shows a sectional view. FIG. 16C shows a top view of theinsertion head of the instrument.

FIG. 17A-C show alternative views of an implant and a guide tubeinsertion instrument in the closed position. FIG. 17A shows a top view.FIG. 17B shows a sectional view. FIG. 17C shows a top view of theinsertion head of the instrument.

FIG. 18 shows a sectional view of a guide tube insertion instrument inassociation with an implant. The guide tube of the insertion instrumentand the screw hole of the implant are misaligned. The set screw is inthe loosened position.

FIG. 19A-B show alternative views of the of the guide tube insertioninstrument of FIG. 18 with an alignment tool. The tool aligns the guidetube of the insertion instrument and the screw hole of the implant. FIG.19A shows a side view. FIG. 19B shows a sectional view. The set screw isin the loosened position.

FIG. 20 shows a sectional view of a guide tube insertion instrument inassociation with an implant. The guide tube of the insertion instrumentand the screw hole of the implant are aligned. The set screw is in theloosened position.

FIG. 21 shows a sectional view of a guide tube insertion instrument inassociation with an implant. The guide tube of the insertion instrumentand the screw hole of the implant are aligned. The set screw is in thetightened position.

FIG. 22 shows a guide tube insertion instrument with an attachedimplant.

FIG. 23 shows an alignment tool.

FIG. 24 shows a top view of the guide tube insertion instrument of FIG.16.

FIG. 25 shows a side view of the guide tube insertion instrument of FIG.16.

FIG. 26 shows a bottom view of the guide tube insertion instrument ofFIG. 16.

FIG. 27A-B shows views of guide tube insertion instruments for left(FIG. 27A) and right (FIG. 27B) anterolateral approaches.

FIG. 28 shows a VAT driver assembly according to one embodiment.

FIG. 29 shows a side view of the engagement between a bone screw and thedriver tip.

FIG. 30 shows a sectional view of the engagement between a bone screwand driver tip.

FIG. 31 shows a view of the c-clip.

FIG. 32 shows a view of the driver tip with the VAT mechanism.

FIG. 33 shows a view of the driver tip with the VAT mechanism, where theVAT sleeve has been removed to show the detail beneath.

FIG. 34 shows a view of the VAT button.

FIG. 35 shows a view of the driver tip including the VAT mechanism,where the VAT sleeve has been removed. The VAT spring is compressed aswhen the bone screw is fully seated.

FIG. 36 shows a detail view of the VAT driver assembly which includesthe driver of FIG. 28 engaged with the 3-hole guide of FIG. 2 and theimplant of FIG. 1.

FIG. 37 shows the VAT driver assembly of FIG. 36 where the VAT sleevehas been translated proximally relative to the driver due to insertionof the screw.

FIG. 38 shows the VAT driver assembly of FIG. 36 where the VAT sleevehas been removed to show the position of the VAT mechanism when thescrew is fully seated.

FIG. 39 shows an alternative embodiment of a driver with a visualindicator that the screw is fully seated.

DETAILED DESCRIPTION

Illustrative embodiments of the invention are described below. In theinterest of clarity, not all features of an actual implementation aredescribed in this specification. It will of course be appreciated thatin the development of any such actual embodiment, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which will vary from one implementation toanother. Moreover, it will be appreciated that such a development effortmight be complex and time-consuming, but would nevertheless be a routineundertaking for those of ordinary skill in the art having the benefit ofthis disclosure. The implants, inserters and guides disclosed hereinboasts a variety of inventive features and components that warrantpatent protection, both individually and in combination.

With respect to FIG. 1, several views of an exemplary embodiment of aninterfixated interbody implant are shown. The interbody implant 10 maybe constructed of any suitable non-bone composition, including but notlimited to polymer compositions (e. g. poly-ether-ether-ketone (PEEK)and/or poly-ether-ketone-ketone (PEKK)), ceramic, metal and/or anycombination of polymer compositions, ceramic and metal. The spinalfusion implant may be provided with a surface coating (for example,titanium plasma spray) to encourage bone growth onto endplate contactingsurfaces. The spinal fusion implant 10 of the present invention may beprovided in any number of shapes and sizes depending upon the particularsurgical procedure or need. By way of example only, the spinal fusionimplant 10 may have a width ranging between 8 and 14 mm, a heightranging between 6 and 18 mm, and a length ranging between 20 and 45 mm.

The interbody implant 10 of the present invention includes a top surface12, a bottom surface 14, opposing first and second lateral side walls16, 18, a leading end 20 and an opposing trailing end 22. The spinalfusion implant 10 of the present invention may be used to providetemporary or permanent fixation within an orthopedic target site. To doso, the spinal fusion implant 10 may be introduced into a disc spacewhile locked to a surgical insertion instrument and thereafter employedin the proper orientation and released. Once deposited in the discspace, the spinal fusion implant 10 of the present invention effectsspinal fusion over time as the natural healing process integrates andbinds the implant.

The top and bottom surfaces 12, 14 are configured to engage thevertebral bodies adjoining the target disc space. Accordingly, the topand bottom surfaces 12, 14 each preferably include a plurality ofanti-migration features designed to increase the friction between theinterbody implant 10 and the adjacent contacting surfaces of thevertebral bodies. Such anti-migration features may include ridges (orteeth) 24 provided along the top surface 12 and/or bottom surface 14.The friction prohibits migration of the implant 10 after insertion intothe intervertebral space and during the propagation of natural bonyfusion. It should be appreciated by one skilled in the art that suchridges (or teeth) 24 can be oriented in a particular direction whichwill stabilize the implant in several degrees of rotation duringplacement.

The interbody implant 10 of the present invention may also be providedwith one or more radiographic markers to allow for visual determinationof proper implant placement. The radiographic markers may bemanufactured from any of a variety of suitable radiopaque materials,including but not limited to a metal, ceramic, and/or polymer material,preferably having radiopaque characteristics. The radiographic markersmay be provided in any size or shape suitable to facilitate effectiveand accurate visualization of implant placement.

The interbody implant includes a large fusion aperture 26 extending in avertical fashion between top and bottom surfaces 12, 14. The aperturemay be provided in any number of suitable shapes, including but notlimited to, generally circular, generally triangular, and/or generallyoblong. This single aperture 26 is an additional feature for promotingfusion between the upper and lower vertebral bodies which allows a bonybridge to form though the interbody implant 10.

According to another further aspect of the present invention, thisfusion may be facilitated or augmented by including osteoinductivematerial(s) within the aperture 26 and/or adjacent to the spinal fusionimplant 10. Such osteoinductive materials may be introduced before,during, or after insertion of the spinal fusion implant 10 of thepresent invention, and may include (but are not necessarily limited to)autologous bone harvested from the patient receiving the spinal fusionimplant 10, bone allograft, bone xenograft, any number of non-boneimplants (e.g. ceramic, metallic, polymer), bone morphogenic protein,and bio-resorbable compositions.

First and second lateral side walls 16, 18 are generally parallel to oneanother. The spinal fusion implant 10 may be further provided with oneor more lateral apertures 28 extending generally perpendicularlytherethrough from one lateral side 16 to the other 18, as shown in FIG.1D. The lateral apertures 28 function to provide visualization at thetime of implantation and at subsequent clinical evaluations. The lateralapertures 28 may be provided in any of a variety of suitable shapes,including but not limited to generally circular, generally triangular,generally rectangular, and/or generally oblong, or any combinationthereof. Although the interbody implant 10 herein includes a pair oflateral apertures 28, the spinal fusion implant 10 may include anynumber of lateral apertures 28 as desired.

Based on the generally radiolucent nature of the implant 10, the lateralapertures 36 provide the ability to visualize the interior of theimplant 10 during X-ray and/or other suitable imaging techniques whichare undertaken from the lateral (or “side”) perspective of the implant10. If fusion has taken place, the lateral apertures 28 will provide amethod for the surgeon to make follow up assessments as to the degree offusion without any visual interference from the spinal fusion implant10. Further, the lateral apertures 28 will provide an avenue forcellular migration to the exterior of the spinal fusion implant 10. Thusthe spinal fusion implant 10 will serve as additional scaffolding forbone fusion on the exterior of the spinal fusion implant 10.

The interbody implant 10 further includes one or more screw holes 30angled to allow screws to pass through the holes and when fully seated,engage the vertebral bodies adjoining the target disc space to securethe implant 10 in position. In the exemplary embodiment shown in FIG. 1,the interbody implant has three screw holes 30 a, 30 b, 30 c, as shownmost clearly in FIG. 1C. Two screw holes 30 a, 30 b located proximal toeach of the lateral side walls 16, 18 are oriented at an angle extendingfrom the trailing end 22 to the bottom surface 14. A medial screw hole30 c is located equidistant from the two lateral side walls 16, 18 andis oriented at an angle extending from the trailing end 22 to the topsurface 12. It will be appreciated that other embodiments may havealternative arrangement and number of screw holes depending upon theneeds of a given surgical procedure. As shown most clearly in thesectional view of FIG. 1B, the screw holes 30 of the implant 10 mayinclude an internal spherical surface 38. As described more fully below,the spherical surface may interact with the head of a bone screw 618 andprovide feedback when the screw is fully seated.

As shown in FIGS. 1A and 1C, the interbody implant 10 further includesone or more insertion apertures 32 which extend inwardly in a generallyperpendicular fashion relative to the trailing end 22. In the exemplaryembodiment shown, which is appropriate for an anterior approach, twoinsertion apertures 32 flank the medial screw hole 30 c. The insertionapertures 32 may be provided having any number of suitable shapes orcross-sections, including but not limited to circular or triangular.Insertion apertures 32 are dimensioned to receive and engage with aninsertion instrument during insertion as will be described in greaterdetail below. The location of the insertion aperture 32 will vary inalternative embodiments where the implant is intended for use in ananterolateral, lateral, posterior, or posterolateral approach. Suchmodifications may be made without departing from the scope of theinvention and are within the knowledge of a person of ordinary skill inthe art.

As shown in FIG. 1D, the interbody implant 10 may further includelateral engagement recesses 34 which extend inwardly in a generallyperpendicular fashion relative to the first and second lateral sides 16,18. The lateral engagement recess 34 may be provided having any numberof suitable shapes or cross-sections, including but not limited tocircular or triangular. Furthermore, the lateral engagement recess 34may extend fully or at least partially along the length of the lateralside walls 16, 18. Lateral engagement recess 34 is dimensioned toreceive and engage with an insertion instrument (described below) toprovide steerability and torsional support during insertion as will bedescribed in greater detail below.

With respect to FIGS. 2-6, an exemplary embodiment of an insertion guide100 according to one embodiment is shown. The guide 100 facilitatesinsertion of screws through an interbody implant 10 by providing theideal trajectory for an awl, drill, tap, screw, or other tool. As willbe described further below, the guide 100 may also interact with thedriver 600 to provide feedback during insertion of the screws. It willbe appreciated that the guide 100 is suitable for use in cervical,thoracic, and lumbar applications. It may be used from an anterior,anterolateral, lateral, posterior, or posterolateral approach withoutdeparting from the scope of the invention. Although the guide may bemade of any suitable bio-compatible material, the use of a radiolucentmaterial, such as anodized aluminum allows fluoroscopic visualization ofthe surgical site without the guide 100 blocking the surgeon's view ofanatomical features and other tools. Use of anodized aluminum alsoreduces the weight of the guide 100. In some embodiments, the guide 100may be color-coded to provide a visual indication to the surgical teamas to which guide 100 corresponds to the interbody implant 10 used inthe surgery.

The guide 100 comprises a central body 102 with an upper surface 104,lower surface 106, first lateral side 108, second lateral side 110, adistal end 112, and a proximal end 114. The exemplary guide 100 shown inFIGS. 2-6 includes three guide tubes 118 a, 118 b, 118 c dimensioned toalign with the screw holes 30 a, 30 b, 30 c of the interbody implant 10.The guide tubes 118 are generally cylindrical with a lumen 124 extendingfrom a leading edge 120 aligned with the distal end 112 of the guide 100to a trailing edge 122 of the guide tube 118.

In the exemplary embodiment, two lateral guide tubes 118 a, 118 b arelocated adjacent to the lateral sides of the guide 108, 110 and arearranged at a downward angle with the same degree of tilt as the lateralscrew holes 30 a, 30 b of the interbody implant 10. The medial guidetube 118 c is located equidistant from the lateral sides 108, 110, andis arranged at an upward angle with the same degree of tilt as themedial screw hole 30 c of the interbody implant 10. The guide tubes 118a, 118 b, 118 c each terminate in a leading edge 120 that is flush withthe distal end 112 of the guide body 102. The leading edge 120 of theguide tubes 118 a, 118 b, 118 c interacts with the trailing edge 36 ofthe screw holes 30 a, 30 b, 30 c of the interbody implant 10. When theguide 100 is properly aligned with the implant 10, the leading edge 120of each guide tube 118 a, 118 b, 118 c corresponds to the trailing edge36 of the screw holes 30 a, 30 b, 30 c of the interbody implant and thescrew holes 30 a, 30 b, 30 c and guide tubes 118 a, 118 b, 118 c arealigned in a linear fashion. The trailing edge 122 of the guide tubes118 a, 118 b, 118 c may include crenellations 138 that interlock withcorresponding crenellations 640 on the driver 600 as described below.Alternatively, the trailing edge 122 of the guide tubes may end in analternative geometric surface that may interact with the driver in akeyed mechanism. In some embodiments, the trailing edge 122 of the guidetubes 118 may end in a flat surface.

The guide 100 may further include one or more insertion apertures forengagement with an insertion instrument. In one exemplary embodiment,the guide 100 includes two insertion apertures 116 which extend throughthe guide body 102 from the distal end 112 to the proximal end 114 in agenerally perpendicular fashion relative to ends 112, 114 of the guide100. The insertion apertures 116 are arranged on either side of themedial guide tube 118C. The insertion apertures 116 may be providedhaving any number of suitable shapes or cross-sections, including butnot limited to circular or triangular. Insertion apertures 116 aredimensioned to receive and engage with an insertion instrument(described below) during insertion as will be described in greaterdetail below.

In some embodiments, guide 100 includes an inserter stop 126 thatextends as a tab-like projection from the proximal end 114 of the guidebody 102. The inserter stop 126 has an upper 128 and lower 130 surface.In some embodiments, the upper surface 128 of the inserter stop may bealigned in generally the same plane as the upper surface 104 of theguide body 102. The inserter stop 126 projects from the proximal end 114of the guide at the midpoint of the inserter body 102, equidistant fromthe lateral sides 108, 110 in a generally perpendicular fashion relativeto the proximal end 114. The inserter stop 126 may include an engagementmechanism for securing the guide 100 to the insertion instrument 300.The engagement mechanism may be a spring plunger 132 to allow quickconnection of the guide 100 to the insertion instrument 300. The ballelement 134 of the spring plunger projects below the lower surface 130of the inserter stop 126 and a spring housing 136 projects above theinserter stop 126. In other embodiments, the engagement mechanism may bea keyed tab which projects from the lower surface 130 of the inserterstop interacts with a corresponding slot on the insertion instrument300. In other embodiments, the spring plunger or keyed tab is located onthe insertion instrument 300 and interacts with a corresponding recesson the guide (100).

In an alternative embodiment shown in FIGS. 7-11, the guide 200 includesonly one guide tube 202. The one-tube embodiment is essentially asdescribed above for the three-guide tube embodiments. However, thelateral guide tubes 118 a, 118 b are absent. As shown most clearly inFIGS. 9 and 10, a single guide tube results in a narrower device whichallows the surgeon to visualize the anatomy that is blocked by thelateral guide tubes in the three-tube embodiment described above.

The guide 200 comprises a central body 202 with an upper surface 204,lower surface 206, first lateral side 208, second lateral side 210, adistal end 212, and a proximal end 214. The exemplary guide 200 shown inFIGS. 7-11 includes one guide tube 218 dimensioned to align with themedial screw hole 30 c of the interbody implant 10. The guide tube 218is generally cylindrical with a lumen 224 extending from a leading edge220 aligned with the distal end 212 of the guide 200 to a trailing edge222 of the guide tube 218.

The guide tube 218 is located equidistant from the lateral sides 208,210, and is arranged at an upward angle with the same degree of tilt asthe medial screw hole 30 c of the interbody implant 10. The guide tube218 terminates in a leading edge 220 that is flush with the distal end212 of the guide body 202. The leading edge 220 of the guide tubes 218interacts with the trailing edge 36 of the screw hole 30 c of theinterbody implant 10. When the guide 200 is properly aligned with theimplant 10, the leading end 220 of the guide tube 218 corresponds to thetrailing end 36 of the screw hole 30 c of the interbody implant 10 andthe screw hole 30 c and guide tube 218 are aligned in a linear fashion.The trailing edge of the guide tube 218 may include crenellations thatinterlock with corresponding crenellations on the driver 600 asdescribed below. Alternatively, the trailing edge 222 of the guide tubesmay end in an alternative geometric shape that may interact with thedriver in a keyed mechanism. In some embodiments, the trailing edge ofthe guide tubes may end in a flat surface.

The guide 200 further includes two insertion apertures 216 which extendthrough the guide body 202 from the distal end 212 to the proximal end214 in a generally perpendicular fashion relative to ends 212, 214 ofthe guide 200. The insertion apertures 216 are arranged on either sideof the guide tube 218. The insertion apertures 216 may be providedhaving any number of suitable shapes or cross-sections, including butnot limited to circular or triangular. Insertion apertures 216 aredimensioned to receive and engage with an insertion instrument(described below) during insertion as will be described in greaterdetail below.

The guide 200 includes an inserter stop 226 that extends as a tab-likeprojection from the proximal end 214 of the guide body 202. The inserterstop 226 has an upper 228 and lower 230 surface. The upper surface 228of the inserter stop is generally aligned in the same plane as the uppersurface 204 of the guide body 202. The inserter stop 226 projects fromthe proximal end of the guide at the midpoint of the inserter body 202,equidistant from the lateral sides 208, 210 in a generally perpendicularfashion relative to the proximal end 214. The inserter stop 226 includesan engagement mechanism for securing the guide 200 to the insertioninstrument 300. The engagement mechanism may be a spring plunger 232 toallow quick connection of the guide 200 to the insertion instrument 300.The ball element 234 of the spring plunger projects below the lowersurface 230 of the inserter stop 226 and a spring housing 236 projectsabove the inserter stop 226. In other embodiments the engagementmechanism may be a keyed tab which projects from the lower surface 230of the inserter stop interacts with a corresponding slot on theinsertion instrument 300.

It will be appreciated that alternative embodiments with two or fourguide tubes are within the scope of this disclosure. The implant used inthe surgical procedure, the surgical exposure, and the preferences ofthe surgeon will determine which guide is most appropriate for a givensurgery.

It will be understood that the guides described in the presentdisclosure may be modified to suit a specific surgical approach such asanterior, posterior, lateral, anterolateral, or posterolateral, or maybe used in open or minimally invasive procedures. Such variations areencompassed by this disclosure and are within the skills of a person ofordinary skill.

The interbody implant 10 may be introduced into a spinal target sitethough use of any variety of suitable surgical instruments having thecapability to engage the implant. With respect to FIGS. 12-15, severalviews of an exemplary embodiment of an insertion instrument 300 areshown. According to a broad aspect, the insertion instrument includes aproximal region 302, a distal region 304, and elongate tubular element306, and an inner shaft 308.

The elongate tubular element 306 is comprised of a proximal end 310, adistal end 312, and an inner bore 314 extending between proximal anddistal ends 310, 312. At or near the proximal end 310 is a thumbwheelhousing 316. At or near the distal end 312 is a pair of distal insertionmembers 318. The insertion members 318 are dimensioned to pass throughthe insertion apertures 116, 216 of the guide, and through the insertionapertures 32 of the implant 10. The insertion members 318 have a lengthadequate to pass through the guide 100, 200.

A handle (not shown) is in a fixed relationship with the elongatetubular element 306. The handle may be aligned with the elongate tubularelement 306, but may also be positioned offset from the tubular element306. The handle is also in a fixed relationship with the thumbwheelhousing 316 allowing easy handling by the user. By way of example, thethumbwheel housing 316 holds a thumbwheel 320, a set screw 322, and atleast one spacer 324. The thumbwheel is generally cylindrical with athreaded lumen. Because the handle is fixed, the user has easy access tothe thumbwheel 320 and can easily and stably turn the thumbwheel 320relative to the thumbwheel housing 316. The user may then employ thethumbwheel 320 to rotate the inner shaft 308 thereby advancing andretracting the distal insertion arms 336 as described below.

The elongate tubular element 306 is generally cylindrical and of alength sufficient to allow the device to span from the surgical targetsite to a location sufficiently outside the patient's body so that thehandle and thumbwheel housing 316 can be easily accessed by the user.The inner shaft 308 is sized and dimensioned to be disposed within theinner bore 314 of the elongate tubular element 306. The inner shaft 308is comprised of a proximal end 328, a distal end 330, and threadedintermediate portion 332. The threaded portion 332 engages thethumbwheel 320 to advance and retract the inner shaft 308 within theelongate tubular element 306.

The distal end comprises a distal insertion head 334 and the insertionmembers 318. The insertion members 318 comprise a pair of insertion arms336. The insertion arms 336 each have an outwardly facing engagementprongs 338 at the distal end 340. The proximal end 342 of the insertionarms 336 are longitudinally fixed to the inner shaft 308 such thatrotation of the thumbwheel 320 advances and retracts the insertion arms336. The insertion head has an upper face 344 and a lower face 346. Asshown in FIG. 14, the lower face 346 comprises an engagement element 348for interaction with the insertion guide 200, 300. In some embodiments,the engagement element 348 comprises a recess for receiving the ballelement 134, 234 of the spring plunger 132, 232. In other embodiments,the engagement element 348 may be a keyed slot 350 as shown in FIG. 14,where the slot corresponds to a keyed tab projecting from the lowersurface 130, 230 of the inserter stop 126, 226 of the insertion guide100, 200. Alternative placement of the interlocking features on theguide and insertion instrument are possible. Such variations are withinthe knowledge of persons of skill in the art, and are encompassed by thepresent disclosure.

To prepare the implant 10 for insertion during a surgical procedure, theinsertion arms 336 may be fully retracted by rotation of the thumbwheel320. The insertion members 318 of the insertion instrument 300 arepassed through the insertion apertures 116, 216 of the guide 100, 200.The insertion members 318 are passed into the insertion apertures 32 ofthe implant. The insertion arms 336 are sufficiently flexible thatpassage of the outwardly facing prongs 338 through the insertionapertures 32 of the implant exerts an inward force and compresses theinsertion arms 336 inward sufficiently to allow the prongs 338 to passthrough the aperture 32. The thumbwheel 320 is rotated to extend theinsertion arms 336 until the outwardly facing engagement prongs 338 atthe distal end 340 of the insertion arms pass completely through thetrailing end 22 of the implant 10 and into the fusion aperture 26. Oncethe insertion arms 336 have been extended to the point that theengagement prongs 338 have passed fully through the insertion apertures32, the inward pressure is released and the insertion arms 336 snap backinto position and prevent the implant 10 from disengaging from theinsertion instrument 300 during the insertion process. The thumbwheel320 may be locked in position to prevent further rotation and extensionof the insertion arms 336.

In surgical procedures where access to the surgical site is morelimited, such as when an anterolateral approach is used, it may bepreferable to have an insertion instrument with an integral guide tubeto eliminate the bulkiness that would come from the use of two separateinstruments as described above. FIGS. 16-27 show views of an exemplaryembodiment of an insertion instrument with an adjustable guide tube.

The anterolateral interbody insertion instrument is designed to insertan interbody between two adjacent vertebral bodies. The instrument maybe used to insert an interbody implant and place fixation devices at aparticular trajectory. The instrument removes the need for a separateguide attached to the inserter and fulfills the surgical requirementswith a single instrument. The mechanism for attachment to the interbodyis similar to a standard insertion device, but the instrument alsoincludes an adjustable guide tube for use in pilot hole preparation andscrew placement. The method of using the inserter includes: attachingthe inserter to an interbody of choice, loosening the adjustable guidetube, aligning the guide tube with the interbody screw hole, locking theguide tube in the desired position, and inserting the interbody andscrew according to standard surgical technique.

According to a broad aspect, the insertion instrument 400 includes aproximal region 402, a distal region 404, and elongate tubular element406, and an internal draw rod 408.

The elongate tubular element 406 is comprised of a proximal end 410, adistal end 412, and an inner bore 414 extending between proximal anddistal ends 412, 414. At or near the proximal end 410 is a thumbwheelhousing 416. A handle (not shown) is in a fixed relationship with theelongate tubular element 406 and the thumbwheel housing 416. In someembodiments the thumbwheel housing 416 holds a thumbwheel 420, a setscrew 422, and at least one spacer 424. The thumbwheel is generallycylindrical with a threaded lumen. At or near the distal region 404 ofthe inserter is an insertion head 434 with a medial insertion arm 418and a lateral insertion arm 426. The medial insertion arm 418, is in afixed position and is dimensioned to pass through one of the medialinsertion apertures 32 on the trailing end of the implant 10. Thelateral insertion arm 426 is connected to the internal draw rod 408 at apivot point 452 such that rotation of the thumbwheel 420 translates theinternal draw rod 408 thereby pivoting the lateral insertion arm 426 asdescribed below.

The elongate tubular element 406 is generally cylindrical and of alength sufficient to allow the device to span from the surgical targetsite to a location sufficiently outside the patient's body so that thehandle and thumbwheel housing 416 can be easily accessed by the user.The internal draw rod 408 is sized and dimensioned to be disposed withinthe inner bore 414 of the elongate tubular element 406. The internaldraw rod 408 is comprised of a proximal end 428, a distal end 430 andthreaded intermediate portion 432. The threaded portion 432 engages thethumbwheel 420 to advance and retract the internal draw rod 408 withinthe elongate tubular element 406. When the thumbwheel 420 is rotated,the internal draw rod 408 is translated in a distal direction and thelateral insertion arm rotates about the pivot point 452, resulting inthe lateral arm moving to an open position as shown in FIG. 16A-C. Whenthe thumbwheel 420 is rotated in the opposite direction, the internaldraw rod 408 is translated proximally and the lateral insertion arm 426rotates about the pivot point 452 to return to the closed position asshown in FIG. 17A-C. As shown in FIG. 17A, 17B, when the lateralinsertion arm is in the closed position, the engagement prong 438 at thedistal tip of the lateral engagement arm 426 engages the lateralengagement recess 34 on the implant 10 to secure the connection of theimplant 10 to the insertion tool 400.

The insertion tool 400 also comprises an alignment guide tube 454. Asshown in FIGS. 16-21, the guide tube 454 may be mounted on the insertionhead 434 in a recess located between the insertion arms 418, 426. Theinsertion head 434 comprises a guide tube alignment aperture that passesthrough the insertion head 434 from the upper surface 444 to the lowersurface 446. The insertion head 434 also comprises a set screw aperture466 that extends into the insertion head in direction parallel to theupper 444 and lower 446 surfaces, and perpendicular to and intersectingthe guide tube alignment aperture 458. The set screw aperture isthreaded and is dimensioned to receive a threaded set screw 468 therein.

The guide tube 454 is generally cylindrical with a leading edge 488, atrailing edge 490, and a lumen 460. The trailing edge 490 of the guidetube 454 may include crenellations 484 that interlock with correspondingcrenellations 640 on the driver 600 as described below. Alternatively,the trailing edge 490 of the guide tubes may end in an alternativegeometric surface that may interact with the driver in a keyedmechanism. In some embodiments, the trailing edge of the guide tubes mayend in a flat surface.

The guide tube 454 is fixedly attached to a guide tube post 456. Theguide tube post 456 is dimensioned to pass through the guide tubealignment aperture 458 and allows the adjustment of the guide tube 456in an upward or downward direction by sliding within the aperture 458.In some embodiments there is a small projection 470 at the base of theguide tube post 456 that will strike the lower edge of the tip 472 ofthe set screw 468 to prevent removal of the tube post 456 from theaperture 458. The set screw 468 engages the guide tube post 456 andprevents movement of the guide tube post 456 within the aperture 458.

As shown in FIG. 27A-B, the insertion instrument may be utilized foreither a left-side or right-side anterolateral approach depending uponthe direction of the insertion head 434.

According to one embodiment, the guide tube 454 is aligned with thescrew hole 30 on the implant 10 through the use of an alignment tool 474as shown in FIG. 23. The alignment tool 474 comprises a handle 476 andan alignment rod 478. As shown in FIG. 23, in some embodiments thealignment rod 478 may have a larger diameter 480 at the proximal end ofthe tool, sized for engaging the guide tube 454, and a smaller diameter482 at the distal end, sized for engaging the screw hole 30.

To prepare the insertion device 400 for use in surgery, the thumbwheel420 is rotated to translate the internal draw rod 408 distally and movethe lateral insertion arm 426 to the open position. The medial insertionarm 418 is inserted into the medial insertion aperture 32 of the implant10 and the thumbwheel 420 is rotated in the opposite direction totranslate the internal draw rod 408 proximally and move the lateralinsertion arm 426 to the closed position. The engagement prong 438 willinteract with the lateral engagement recess 34 to secure the implant 10to the insertion instrument 400. It is then necessary to align the guidetube 454 of the insertion instrument 400 with the medial screw hole 30 cof the implant 10. The set screw 468 is loosened and the alignment rod478 is passed into the lumen 460 of the guide tube 454 and then into themedial screw hole 30 c. When the alignment rod 478 is passed throughboth the guide tube 454 and the screw hole 30 c, the two elements arecorrectly aligned. The set screw 468 is tightened and the alignment tool474 is removed. The implant 10 is prepared for use in the surgicalprocedure.

Although the exemplary embodiment of an anterolateral inserter describedherein incorporates an integrated guide tube, in some embodiments it maybe preferable to have a single insertion instrument that may be used foreither a right or left approach. In such a case, the insertioninstrument 400 will not have an attached guide tube. In this way, theupper 444 and lower 446 surfaces of the insertion head 434 will beunencumbered by any protrustions allowing easy reversal of theinstrument. Further, it may be preferable that the insertion instrument400 is compatible with implants of any width. Therefore, in someembodiments, the insertion instrument 400 has two fixed arms thatinteract with the medial insertion apertures on an interbody implant. Inthis way, the pivoting lateral insertion arm 426 does not restrict theinterbody implant 10 to a specific width, and a single inserter may beused for the insertion of implants of different sizes at differentlevels if necessary.

The insertion instruments described herein may be utilized to place aninterbody implant between vertebral bodies. The guides disclosed hereinwill provide an ideal trajectory for placement of the screws to securethe implant in place. The screws may be placed by a driver which screwsthe anchor portion of the bone screw into the vertebral body. The driveralso contains an internal hexabit driver for placement of set screws.However, one of the issues with placement of screws is that it is oftendifficult for the surgeon to know that screws are fully seated whichleads to screws left proud, or screws stripped in bone. Previous methodsto identify proper seating of screws have used saw teeth on guides toprovide a hard stop. However, such devices do not provide visual oraudible indication, and the tactile stop is limited to when the teethcome into contact. Another method that has been used is blasting thesurfaces of screws and plates to introduce roughness and provide sometactile feel when the roughened surfaces are in contact. However, thismethod does not include hard stop or visual or audible alert.

Disclosed herein is a visual, audio, and touch (VAT) mechanismintegrated into the body of a driver that provides feedback to thesurgeon when the screw is properly set. Use of a visual, audio and touchmechanism ensures the screw is fully seated, but not over tightened.

As shown in FIG. 28, an otherwise standard driver may incorporate any orall of the visual, audio, or touch mechanisms disclosed herein.

According to a broad aspect, the driver 600 has a proximal end 602, adistal end 604, and a central shaft 606. A handle 608 is located at theproximal end 602. A driver tip 610 and a hexabit driver 616 are locatedat the distal end 604. The proximal end further comprises a firstrotation grip 612 for the driver tip 610, and a second rotation grip 614for the hexabit driver 616. Each of the feedback mechanisms describedherein is incorporated into the distal end of the driver as will bedescribed more fully below. It will be understood that the presentdisclosure is described in relation to an angled driver. However, thefeatures may be incorporated into a driver of any suitable shape. Suchvariations are encompassed by this disclosure and are within the skillsof a person of ordinary skill.

FIGS. 29 and 30 show a detailed view and sectional view of the bonescrew 618, bone anchor set screw 620, and the driver tip 610. The bonescrew 620 has a crenellated head 622 and a threaded recess 624 toreceive the set screw 620. As shown in FIG. 30, the set screw 620 has ahex recess 628 and a tapered head 626 that is dimensioned to fit insidethe driver tip 610. The driver 600 has crenellations 630 at the drivertip 610 wherein the crenellations are complementary to the crenellatedhead 622 of the bone screw 620. When properly aligned, the crenellationsare interdigitated and secure the connection between the driver 600 andbone screw 618. This secure connection translates the torsional forcefrom the rotation of the first rotation grip to drive the bone screw 618into the vertebral body. The driver 600 also comprises a hexabit driver616 as shown in FIG. 30. The hexabit driver 616 interlocks with the hexrecess 628 of the set screw 620. The rotation of the second rotationgrip 614 drives the threaded set screw 620 into the threaded recess 624of the bone screw 618. The c-clip 632 shown in FIGS. 30 and 31 functionsto grip the set screw head 626 to stabilize the connection between theset screw 620 and the driver 600. The oblong shape of the c-clip 632,retains the clip centered in the driver 600 while ensuring engagementwith the set screw heads 626 on the narrow sides.

In one exemplary embodiment, the driver further comprises an indicatorthat the screw is properly seated. The indicator may be a visual, audio,and touch (VAT) mechanism 634 that provides feedback to the surgeon whenthe screw is properly set. As shown in an exemplary embodiment in FIG.32, the VAT mechanism 634 comprises a button 636, a sleeve 638, and VATcrenellations 640. The VAT sleeve 638 is rotatable and translatableabout the driver 600. The VAT button 636 is contained in the VAT sleeve638 and rotates and translates with the sleeve 638. The distal end 642of the VAT sleeve 638 terminates in the VAT crenellations 640.

FIG. 35 shows the VAT mechanism 634 with the VAT sleeve 638 removed. Asshown, beneath the VAT sleeve 638 is the VAT sleeve spring 648 whichencircles the internal splines 650 of the VAT mechanism. The VAT sleevespring 648 forces the sleeve 638 distally relative to the driver 600. Asthe bone screw 618 is driven into the vertebral body, the VAT sleevespring 648 will be compressed and the sleeve 638 will translateproximally relative to the driver 600. Beneath the VAT sleeve spring 648is the internal spline 650 comprising a plurality of longitudinalgrooves 652 arranged around the circumference of the driver 600. Thespline 650 is held in place by a spline pin 656. The spline 650 also hasan internal slot 654, as shown in FIG. 35. The spline pin 656 cantranslate through the slot 654 which allows the spline 650 to rotate thelength of the slot 654.

The VAT button 636 further comprises a button spring 646 and a buttontooth 644. The button spring forces the VAT button 636 outward. The VATbutton 636 rests on the driver 600 when the VAT sleeve 638 is in thedistal position. The insertion of the screw results in compression ofthe sleeve spring 648 and proximal translation of the VAT sleeve, untilthe button tooth 644 engages the spline.

FIGS. 36-38 show the driver 600 in use with a 3-tube guide as describedabove. Screw placement begins with the insertion of an interbody betweenintervertebral discs. As shown in FIG. 36, the insertion guides andinsertion instrument with guides described herein may be use. The bonescrew 618 with set screw 620 are affixed to the distal end 604 of thedriver 600 and are held in place by the c-clip 632 which engages thehead of the set screw 626. The driver 600 and bone screw 618 areinserted through the guide tube 118 and through the screw hole 30 of theinterbody implant 10 to the location where the bone screw 618 will beinserted.

The guide tubes 118 described herein have crenellations on the trailingedge 222 of the tubes (as shown for example in FIGS. 2 and 16). Theguide tube crenellations 138 are complementary to the VAT crenellations640 such that proper alignment of the guide tube 118 and VAT driver 600will lead to the interdigitation of the crenellations. When the VATdriver 600 is seated with the guide tube 118 prior to insertion of thescrew, the VAT sleeve 638 is in the distal position as shown in FIG. 36.The first rotation grip 612 is rotated to drive the screw 618 distallyinto the vertebral body. Because the guide tube crenellations 138 andthe VAT crenellations 640 maintain the guide tube 118 and VAT sleeve 638in a fixed position relative to one another, translation of the bonescrew 618 in the distal direction results in compression of the sleevespring 648 and proximal translation of the VAT sleeve 638 relative tothe driver, as shown in FIG. 37.

The VAT mechanism 634 provides three indicators to the surgeon that thebone screw 618 is properly seated. When the screw 618 is sufficientlytranslated so that it interacts with the spherical surface 38 of thescrew hole 30 of the implant 10, the VAT button 636 which translatesproximally with the VAT sleeve 638, reaches the spline 650. The tensionon the button spring 646 will cause the VAT button 636 to pop outproviding both an audible and visual indicator that the bone screw 618is properly seated. Additionally, when the VAT button 636 pops out, thebutton tooth 644 will engage the spline 650. The spline 650 can rotateagainst the sleeve spring 648 until the end of the spline slot 654reaches the spline pin 656. When the spline pin 656 reaches the end ofthe spline slot 654, the spline 650 prevents the driver from furtherrotation to drive the screw, resulting in a hard tactile stop. Thetactile alert of the hard stop is regulated by the length of the splineslot 654. Thus the delay between button tooth engagement and hard stopmay be increased or decreased by adjusting the length of the spline slot654. Such variation can ensure full engagement of teeth, and provide adelayed response if desired to accommodate tolerance stack.

The VAT mechanism 634 as described in this exemplary embodiment providesvisual and audible indications that the screw is properly set in theform of the VAT button popping out, and a tactile indication in the formof a hard stop when rotation will no longer occur. Once these indicatorsare received, the surgeon will rotate the second rotation grip to placethe set screw 620. While the embodiment described herein encompassesvisible, audible, and tactile indicators that a screw is fully set,other embodiments may involve any visible, audible, or tactileindicators, alone or in combination. For example, one embodiment maycomprise the hard stop of the spline, but without the visual and audibleindicator of the button. Alternatively, another embodiment may comprisethe button to provide a visual and audible indication, but without thetactile component of a hard stop.

While the embodiments described herein have interlocking crenellationson the guide 100 and driver 600, alternative interlocking mechanisms maybe used. In one alternative embodiment, the sleeve 638 and trailing edgeof the guide tube 122 have a keyed interlocking mechanism to secure theconnection during installation of the screws 618. The pattern may be ofany form, so long as the patterns of the sleeve 638 and guide tube 122are complementary. In other embodiments, the sleeve 638 and trailingedge of the guide tube 122 may be smooth and without interlockingfeatures at all. In such embodiments, the interaction between thecrenellated driver tip 610 and the crenellated bone screw 618 stabilizesthe connection between the driver 600 and guide 100.

Additionally, alternative visual indicators may be used. Further, whilethe exemplary embodiment described has a VAT mechanism 634 containedwithin a translatable sleeve 638, other mechanisms are possible which donot require the bulk of a sleeve 638 external to the driver 600.

For example, the embodiment shown in FIG. 39 comprises a colored band asa visual indicator. In this exemplary embodiment, the driver tip 610 istranslatable relative to the body of the driver 600. A colored band 658is proximal to the driver tip 610 and the outer diameter of the coloredband 658 is smaller than the inner diameter of the driver tip 610. Asthe bone screw 618 is inserted, the outer tip 610 translates proximallyrelative to the driver 600 and the colored band 658 is covered by thedriver tip 638. When the colored band 658 is no longer visible, the bonescrew 618 is properly seated and the set screw 620 may be placed.

While the exemplary embodiment includes a guide between the screw driverand the interbody device (the ultimate destination of the screw) it isfurther contemplated that the interbody may have a direct interactionwith the VAT mechanism in instances when there is no intermediate guidestructure between the interbody or plate and the screw driver. In someembodiments, crenellations could be manufactured into the interbody orplate to provide an interlocking surface for engagement of the interbodyand the VAT mechanism.

Other combinations of visual, audible, and tactile indicators arepossible and are within the scope of this disclosure. The indicators maybe components of an external sleeve, or may be internal components whichallow translation of the driver tip. Such variations are within theknowledge an ability of one in the skill in the art.

What is claimed:
 1. An insertion guide providing an ideal trajectory forplacement of instruments during implantation of an interbody implant ina spinal surgery comprising: a central body with an upper surface, lowersurface, first lateral side, second lateral side, a distal end, and aproximal end, wherein an insertion aperture extends through the centralbody from the distal end to the proximal end; an inserter stop tab whichextends proximally from the upper surface of the proximal end of thecentral body; and one or more cylindrical guide tubes with a leadingedge and a trailing edge, and with a lumen extending from the leadingedge to the trailing edge, wherein the leading edge of the guide tubesaligns with one or more screw holes of an interbody implant, and whereinthe guide tubes are fixed at a predetermined angle which corresponds toa screw hole angle of the interbody implant.
 2. The insertion guide ofclaim 1, wherein the trailing edge of the guide tube has a geometricsurface.
 3. The insertion guide of claim 2, wherein the trailing edge ofthe guide tube has crenellations.
 4. The insertion guide of claim 1,wherein the insertion guide is radiolucent.
 5. The insertion guide ofclaim 4, wherein the insertion guide is aluminum.
 6. The insertion guideof claim 1, wherein the inserter stop tab comprises an engagementmechanism which interlocks with an insertion instrument.
 7. Theinsertion guide of claim 1, wherein the insertion guide has one guidetube.
 8. The insertion guide of claim 1, wherein the insertion guide hasthree guide tubes.
 9. An insertion instrument providing an idealtrajectory for placement of instruments during implantation of aninterbody implant in a spinal surgery comprising: a proximal region, adistal region, and an elongate tubular element, wherein the elongatetubular element comprises a proximal end, a distal end, and an innerbore extending between the proximal and distal ends; a thumbwheelhousing near the proximal end which contains a generally cylindricalthumbwheel with a threaded lumen; an internal draw rod sized anddimensioned to be disposed within the inner bore of the elongate tubularelement, wherein the internal draw rod comprises a proximal end, adistal end, and a threaded intermediate portion which passes through andengages the threaded lumen of the thumbwheel, wherein rotation of thethumbwheel translates the internal draw rod; an insertion head with anupper surface, a lower surface, a leading end, and a trailing end, amedial insertion arm and a lateral insertion arm extending distally fromthe leading end of the insertion head, wherein the medial insertion armis in a fixed position and the lateral insertion arm is attached to theinsertion head at a first pivot point such that translation of the drawrod causes the lateral insertion arm to pivot about the pivot point; andan alignment guide tube connected to the upper surface of the insertionhead in an angled position, wherein the guide tube is generallycylindrical with a leading edge, a trailing edge and a lumen, and theleading edge of the guide tube is sized and positioned to align with ascrew hole on an interbody implant.
 10. The insertion instrument ofclaim 9 wherein the angled position of the guide tube is adjustable. 11.The insertion instrument of claim 10 further comprising: an apertureextending through the insertion head from the upper surface to the lowersurface, and a set screw recess extending distally from the trailing endof the insertion head perpendicular to and interconnecting with theaperture; and the guide tube connected to the insertion head at a secondpivot point and the guide tube fixedly attached to a guide post sizedand dimensioned to pass through the aperture in the insertion head,wherein a set screw inserted into the set screw aperture contacts theguide post to restrict movement of the guide tube.
 12. The insertioninstrument of claim 9 wherein the trailing edge of the guide tube has ageometric surface.
 13. The insertion instrument of claim 9 wherein thetrailing edge of the guide tube has crenellations.
 14. A driver forinsertion of bone screws during spinal surgery comprising: a proximalend, a distal end, and a central shaft; a driver tip and a hexabitdriver located at the distal end; a first rotation grip and a secondrotation grip located at the proximal end, wherein rotation of the firstrotation grip translates the driver tip and rotation of the secondrotation grip translates the hexabit driver; and an indicator that ascrew is properly seated, wherein the indicator provides at least one ofa visual, audible, or tactile indication to a user.
 15. The driver ofclaim 14, further comprising: the driver tip is translatable relative tothe central shaft; the indicator is a colored band on the central shaftproximal to the driver tip, wherein an outer diameter of the coloredband is smaller than an inner diameter of the driver tip; and whereininsertion of a screw causes proximal translation of the driver tip suchthat the driver tip overlaps the colored band when the screw is properlyset.
 16. The driver of claim 14, wherein the indicator comprises abutton that provides audible and visible indications.
 17. The driver ofclaim 14, wherein the indicator prevents further rotation of the driverthat provides a tactile indication.
 18. The driver of claim 14, whereinthe indicator comprises: a sleeve located at the distal end of thedriver proximal to the driver tip, said sleeve being rotatable andtranslatable relative to the driver; a button located beneath thesleeve, wherein said button translates and rotates with the sleeve, thebutton further comprising a button spring and a button tooth; aninternal spline located beneath the sleeve comprising a plurality oflongitudinal grooves arranged around the circumference of the distal endof the driver, a spline slot, and a spline pin; a sleeve spring woundaround the spline; wherein insertion of the screw results in proximaltranslation of the sleeve and compression of the sleeve spring, andwherein when the screw is properly seated, the button provides anaudible and visual indication and engagement of the spline pin with thespline slot prevents further rotation and providing a tactileindication.
 19. The driver of claim 18, further comprising crenellationsat a distal edge of the sleeve, wherein said crenellations arecomplementary to crenellations on an insertion guide.